Car immobilizer

A starter motor immobilizer is
an effective (but not certain)
means of protecting your car
against theft. It has the drawback
that a would-be thief will
try to render it inoperative and
in the process damages your car.
The present circuit is a simple
version of car immobilizer and
tends to confuse the thief. This
is because the car appears to
function normally, but it does
not start. Has it broken down or
is there some sort of protection
circuit active?